1. Field of the Invention
The present invention relates to a process for effectively removing unreacted oil from an anionic surfactant slurry containing the same.
2. Description of the Prior Art
Various methods for removing unreacted components from anionic surfactant slurries are known in the art. Known methods are, for example, those in which unreacted oil is extracted with an organic solvent (i.e., an extraction method), an anionic surfactant slurry is steam distilled under normal pressures (i.e., a steam distillation method), an anionic surfactant slurry is stripped after adding a polyol or polyoxyalkylene alkyl ether as disclosed in U.S. Pat. No. 3,893,940 (i.e., a stripping method), and unreacted oil is adsorbed by adding activated carbon to an anionic surfactant slurry as disclosed in Japanese Examined Patent Publication (Kokoku) No. 56-8026 (i.e., an adsorption method). However, the extraction and stripping methods involve a problem in that complete removal of the organic solvent used is difficult so that a solvent odor is remained in the product. The adsorption method requires the separation and removal of the activated carbon used, which operation is troublesome. On the other hand, although the steam distillation method does not involve the above-mentioned problems, this method is not economical since a large amount of steam is consumed and is not effective since foaming or a similar phenomenon occurs due to the presence of a surfactant during the operation.